She is a pretty detective with the Tokyo police, who often uses the City Hunter team to do her job for her. She keeps promising to pay back Ryo with "mokkori" (sex), but always manages to get out of it. Despite her deceptive tendencies, she and Ryo have a considerable history together, and was in a love triangle with Ryo and Hideyuki Makimura.

Saeko's father is the chief of police, so she has some leeway in how she does her job. But off the job, her father puts the pressure on her to get married.

In the spin-off Angel Heart, Saeko was the chief of police who used to date Hideyuki Makimura and was implied to be waiting for Hideyuki's proposal. In later chapters, Saeko's hidden dream was to have a normal family with Ryo, implying her shift in romantic interest.